Using Session array to maintain data across the pages

Session Array Array can store more items or data in a single variable but these are not available in different pages for use. Any ordinary ( or normal ) array will loose its data as page execution ends. We have to transfer the array each time the visitor moves away from one page to other. In some applications we need to retain the data as long as the visitor is active at site. Shopping cart is the best example for this. Visitor moves between different pages and adds items to the shopping cart. We have to carry the shopping cart to all the pages along with the visitor. Visitor can add or remove items from the cart from any page. We need a session array to retain the data in different pages. Session arrays are like session variables which maintain a unique link between user's web page and the server. You can read more on session management here.

Let us start with declaring a session array. Before that we have to start the session by adding this line at the top of the page
session_start();
Next, any where inside the page we can declare the array (if not done before ) before using. ( Start the shopping cart )
$_SESSION[cart]=array();
Here we have declared a session array. We can add elements to it by array_push function.
array_push($_SESSION[cart],$prod_id);
We can remove items from the array by using array_diff function.
$_SESSION[cart]=array_diff($_SESSION[cart],$prod_id);
This way we can add or remove items from out session array. We will use this in our shopping cart script.

Multidimensional Session Array

Session Array
We can use multidimensional array to store more than one attributes of an element. We may require to store a product along with the user selection of quantity ( or colour ) in a session array.

Here is how to create multidimensional session array
$_SESSION['cart']=array(array("product"=>"apple","quantity"=>2),
array("product"=>"Orange","quantity"=>4),
array("product"=>"Banana","quantity"=>5),
array("product"=>"Mango","quantity"=>7),
); 

Display elements of the array

$max=sizeof($_SESSION['cart']);
for($i=0; $i<$max; $i++) { 

while (list ($key, $val) = each ($_SESSION['cart'][$i])) { 
echo "$key -> $val ,"; 
} // inner array while loop
echo "<br>";
} // outer array for loop

Add element to this array

$b=array("product"=>"$product","quantity"=>$quantity);
array_push($_SESSION['cart'],$b); // Items added to cart

Remove elements to this array

unset($_SESSION['cart'][$val1]);// $val1 is the key  of the element
We used above codes in our shopping cart script, you can download and check the outputs
Visitors Rating
Your Rating





restroika

29-05-2010

How max limit of the Array Session and Array? Where can i test if the one variable is more than the max. limir? Thank.
Mohamed Yousufdeen

08-08-2014

sir,let me know how to create associative session array and how to manipulate that
ravi

10-03-2015

$_SESSION is it self array or we have to make it array
smo

13-03-2015

Yes , you can loop through and display all elements of the session array check the last part.
uday kiran

11-04-2016

if i m writing array_push($_SESSION[cart],$prod_id);
in this manner the second pushed element is overwriting the first element
smo1234

11-04-2016

No that can never happen, array_push($_SESSION['cart'],'AAA','BBB','CCC'); array_push($_SESSION['cart'],'Orange'); Second line ads fourth element to the array of cart, it is not removing any item.
frank

20-04-2016

uday kiran is right, though it is not actually overwriting.
Every time the array is declared, a new empty array is created, so array_push() is in fact pushing the first $prod_id to that empty array.
This can be avoid by declaring the array only if it was not already set:

if(!isset($_SESSION[cart]))
$_SESSION[cart]=array();
smo1234

09-05-2016

No that is not correct. To make it clear one more page cart-add.php is added to the script. This page shows one input box and user can enter product through this to the cart. This will not overwrite any previously stored elements in the cart. It is adding a new one.

This explanation is added in demo script also. You can download a fresh copy of the script and check.

Note that we are declaring the array only once, in cart.php page. This is not to be declared in any other page. If you want to destroy this cart then you can use
unset($_SESSION['cart']);

Check the demo page.
Chan

28-11-2018

Could you help to do it with the codeigniter?

Post Comment This is for short comments only. Use the forum for more discussions.




HTML MySQL PHP JavaScript ASP Photoshop Articles FORUM . Contact us
©2000-2019 plus2net.com All rights reserved worldwide Privacy Policy Disclaimer